running lean... any help??

[upshiftN]

Yeah so i'm not too sure if i'll be runnin lean here, but i'm about to buy an apexi n1 exhaust system with apexi downpipe. I already have an injen intake, and a greddy type s bov. I've already been told by a friend who usually knows what he's talkin' about, that i'll be running lean. Would it be then good to add a new fuel pump? Or maybe some new injectors? I just wanna keep it from running lean once this catback gets thrown on there. Any suggestions?

 

[DSMJim]

A catback will not cause your car to run lean. The injectors in our cars are sized large enough that 50-60extra hp is capable before they need to be swapped (well more sometimes) so adding an intake and exhaust will not make your car run lean. Not sure what your friend is talking about but that's not true. It will allow your turbo to spool faster, but it's not going to make it force more air into the motor. Your wastegate regulates that no matter what so the car can't run lean simply by adding bolt ons. It will make more HP but again that air fuel ratio is controlled by what the MAF and O2 sensors see.

 

[upshiftN]

Yeah, sorry if i sound kinda ignorant here, but what's MAF, i've been wonderin what that was for a while now after reading a few posts. And what would cause my car to run lean, like i know it's cause of the more air then fuel ratio, but what physically like types of mods would cause it to run lean?

 

[Stanford]

If you try to run more boost than your fuel system can support you will run lean. The most common mod for running lean in my opinion would be people who upgrade thier turbo and try to run lots of boost with no fuel mods. Your MAF is your factory air metering device which tells your ECU how much air enters your engine. As more air enters the MAF the ECU sends more fuel to correct your A/F ratio. Your ECU can only add so much fuel though, at which point you will need to upgrade. I would start with a Fuel pump and go from there. If you don't know where your MAF is its the Device mounted between your Air-box and Intake pipe.